In the Linux kernel, the following vulnerability has been resolved:

platform/x86: bitland-mifs-wmi: Fix NULL pointer dereference during suspend/resume

The driver registers two distinct WMI devices: a control device
(BITLAND_WMI_CONTROL) and an event device (BITLAND_WMI_EVENT). During
the probe phase, the event device handling path returns early before
initializing the platform profile device (data->pp_dev), leaving it
NULL.

However, the PM sleep operations are registered globally for the WMI
driver and are triggered for both devices. When entering suspend, the
event device invokes bitland_mifs_wmi_suspend(), which passes the
uninitialized data->pp_dev (NULL) into laptop_profile_get(). This leads
to a NULL pointer dereference inside dev_get_drvdata(), causing a
kernel Oops and halting the suspend sequence.

Fix this by adding a validity check for data->pp_dev in both the suspend
and resume callbacks, safely skipping profile operations for the event
device.